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Napa city parks staff scale back Roundup use

Workers with the Napa city parks department are phasing in techniques to control weeds at local recreational areas without the use of glyphosate, a widely used herbicide sold under the Roundup brand name. 

Submitted photo

Starting this month, glyphosate, better known as Roundup, has been added to the list of chemicals known to the state to cause cancer for purposes of Proposition 65 by the California Office of Environmental Health Hazard Assessment, the Napa County Agricultural Commissioner’s office said.

The addition of glyphosate, a commonly used ingredient in many weed killers or herbicides commonly used in agricultural, industrial and residential settings, means any product containing the chemical that is sold or used in California must include a Proposition 65 warning on the label.

The warning language will generally state the product contains glyphosate, a chemical known to the State of California to cause cancer, birth defects, or other reproductive harm.

Currently, there are over 900 chemicals or things on the Proposition 65 list, including acetaminophen (Tylenol), alcoholic beverages, aloe vera, Alprazolam (Xanax), aspirin, boric acid, caffeine, diazepam (Valium), gasoline and diesel engine exhaust, estrogen, lead, marijuana and tobacco smoke, ultraviolet light, as well as home-use, industrial and agricultural compounds, the ag commissioner said.

In Napa, the city’s parks department is reducing the use of glyphosate in parks and public areas after residents raised concerns.

Voters approved Proposition 65, also known as the Safe Drinking Water and Toxic Enforcement Act of 1986, to help Californians make informed decisions about protecting themselves from chemicals known to cause cancer, birth defects, or other reproductive harm. The addition of glyphosate to the list, therefore, does not imply the chemical should not be used or banned.

The greatest risk of any pesticide is to the person who is mixing, loading, or applying the material. Users of glyphosate herbicides may mitigate their exposure to the chemical by following the product labeling, including the wearing of any required personal protective equipment, such as chemical resistant gloves.

In addition, California has the most comprehensive pesticide regulatory program in the world designed to mitigate potential hazards posed by pesticides and protect human health and the environment. The Napa County Agricultural Commissioner’s Office is responsible for implementing the state regulatory program at the local level, ensuring the safe use of pesticides in all settings in the county.

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The Environmental Protection Agency (EPA) has established safe levels for glyphosate in more than 150 foods and beverages. Experts say tiny levels in wine, if present, pose no risk to wine drinkers. An adult would have to drink 2,500 glasses of wine a day containing the highest glyphosate residue measured, every day for 70 years to reach the EPA’s threshold for health concern, the county’s news release said.

Glyphosate has been marketed and used for approximately 40 years. The herbicide has very low acute toxicity to humans and other mammals and the environment. In addition to agriculture, the material is widely sold at home improvement centers, landscape supply and plant nursery businesses and many other retail outlets. Estimates are that sales and use of the herbicide statewide are split evenly between agriculture and non-agriculture (i.e., home use, landscaping, etc.).

According to the California Department of Pesticide Regulation, glyphosate is relatively nonleachable, has a low tendency to runoff, and is readily broken down by microbial action. Glyphosate is relatively immobile in most soil environments as a result of its strong adsorption to soil particles and therefore unlikely to enter ground or surface water, the county news release said.

Any off-site movement of the glyphosate can be reduced by following use requirements and safeguards listed on product labeling. Napa County’s Conservation Regulations and the Erosion Control plans that implement the regulations further protect surface water by reducing sediment movement and by intercepting sediment before it reaches watercourses.

Landowner participation in environmental stewardship programs, such as Napa Green, LandSmart, and Fish Friendly Farming, further reduce the potential for erosion and off-site movement of pesticides and any related residues.